The present invention relates to a toner supply container for supplying toner to an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer. It also relates to an image forming apparatus in which such a toner supply container is removably installable.
An image forming apparatus to which the present invention is preferably applicable is of a type which employs an electrophotographic image formation system to form images on a piece of recording medium. As examples of an electrophotographic image forming apparatus, there are electrophotographic copying machines, electrophotographic printers (laser beam printers, LED printers, or the like), facsimile machines, word processors, and the like.
Conventionally, toner in the form of microscopic particles has been used as developer for an image forming apparatus such as an electrophotographic copying machine or printer. After the depletion of the developer (toner) within the main assembly of an image forming apparatus, a toner supply container is used to replenish the image forming apparatus with a fresh supply of toner. Since toner is in the form of extremely microscopic particles, it tends to easily scatter, creating a problem. Thus, an operator, and/or the environment in which the operator works, tends to be contaminated with toner which is being replenished, or a small amount of the toner which remains in a toner supply container after replenishment, scatters.
In the case of a method for sealing the toner outlet of a toner supply container by welding a piece of film across the outlet, the container cannot be resealed, after usage, to solve the above described problem. Therefore, it has been proposed, and also put to practical use, to provide a toner supply container with a shutter so that the toner discharging outlet of a toner supply container can be repeatedly opened or closed (sealed).
On the other hand, it has been a common practice to provide the toner supplying apparatus of an image forming apparatus, through which toner is received by the image forming apparatus, with a shutter so that the toner supply inlet of the toner supplying apparatus can be repeatedly opened or sealed. This arrangement makes it possible to keep the toner supplying apparatus sealed except for while the toner is being supplied, so that foreign substances such as dust, or foreign objects such as paper clips, are prevented from entering the toner supplying apparatus, and so that it is assured that the toner supplying apparatus is not supplied with wrong type of toner or a wrong amount of toner.
Further, it has been proposed, and also put to practical use, to engage the aforementioned shutter of a toner supply container with the shutter of the toner supplying apparatus, in such a manner that both shutters can be opened or closed together. This arrangement further assures that toner is prevented from scattering while the toner is being supplied, preventing thereby an operator or the adjacencies of the image forming apparatus from becoming contaminated with toner.
In order to open or close the shutter of the toner supply container and the shutter of the toner supplying apparatus on the main assembly side, the toner supply container is provided with a handle, which is a rotational member, so that the shutters are opened or closed by a rotational force transferring means, such as a gear train, with which the image forming apparatus is provided.
If the drive train through which driving force for opening or closing the shutters is transmitted from the handle to the shutters is constructed with low cost, that is, without using high precision components, it is virtually impossible to avoid such a problem that the components fit loosely with each other, which results in an excessive amount of play, causing thereby gear backlash and/or distortion of the driving train. With the components of the drive train fitting loosely, the ratio between an input stroke and an output stroke does not become 1:1. Thus, the opened shutter sometimes fails to be returned to the original position, that is, the original closed position. If a toner supply container, which was pulled out of the image forming apparatus main assembly, in such a condition, is reinstalled into the main assembly, and then, the shutter is reopened and closed, the distance by which the shutter fails to be returned to the closed position increases, as compared to the preceding opening and closing. With the repetition of the supplying of the apparatus with toner, the distance by which the shutter fails to be returned to the closed position keeps on increasing.
In particular, in the case of a toner supplying system in which the shutter on the main assembly side and the shutter on the toner supply container side are engaged with each other to be moved together, misalignment may occur between the two shutters, which makes it impossible to pull the toner supply container out of the image forming apparatus main assembly, or causes the shutter on the main assembly side to fail to return to the closed position, making it impossible to install a brand-new toner supply container (whose shutter is at the original position, or the correct position). This is a problem.
The primary object of the present invention is to provide a combination of a toner supply container and an image forming apparatus, which makes the driving force transmitting portion of the rotational member engage with the rotational force transmitting means, always at the same position.
The second object of the present invention is to provide a combination of a toner supply container and an image forming apparatus, by which the toner supply container shutter can be smoothly opened or closed.
The third object of the present invention is to provide a combination of a toner supply container and an image forming apparatus, which causes the opened toner supply container shutter to always return to the original position, or the original closed position, as it is closed.
The fourth object of the present invention is to provide a combination of a toner supply container and an image forming apparatus, which does not suffer from a problem that the toner supply container cannot be installed into, or removed from, the main assembly of an image forming apparatus because of the misalignment between the shutter on the toner supply container side and the shutter on the apparatus main assembly side.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.